This Background is intended to provide the basic context of this patent application and is not intended to describe a specific problem to be solved.
Digital media players are in common use among a broad base of users. Presently, streaming digital media is available over both wireless and wired networks and may be displayed on cellular telephones and other portable media devices. Media players may send and receive content over a variety of data networks including cell-based and isochronous networks. The IEEE 802 standard family describes various local and wide-area networks (LAN and WAN, respectively) that carry variable-sized packets encoding digital media. The 802 standard encompasses protocols for both wired (e.g., 802.3, or Ethernet) and wireless (e.g., 802.11, or “WiFi”) networks. The 802.11 standard describes the protocols used to transfer data when a device is connected to a wireless network.
The station is the most basic component of the wireless network and is any device that contains the functionality of the 802.11 standard and a connection to the wireless device. Typically the 802.11 functions are implemented in the hardware and software of a network interface card (NIC). A station could be a media player, a laptop PC, handheld device, or an Access Point. Stations may be mobile, portable, or stationary and all stations support the 802.11 services of authentication, de-authentication, privacy, and data delivery. A collection of any number of stations is called a Basic Service Set (BSS). Generally, stations communicate by connection to other stations in an independent BSS, or ad-hoc network, or by connections to a central access point in an infrastructure BSS.
To connect to a network, devices typically perform an authentication and association process. Before communicating any data, clients and access points must establish a relationship, or association. Typically, however, only after association may devices exchange data. In the Infrastructure Basic Service Set, clients first associate with an access point. However, in an ad-hoc topology, devices must associate with other devices. To associate, the communicating devices exchange messages called management frames. All wireless devices transmit a beacon management frame at a fixed interval and a client listens for beacon messages to identify the devices within range. The client then selects the BSS to join based on the information contained in the management frame. A client may also send a probe request management frame to find an access point affiliated with a desired network name. After identifying an access point or another device, the client and the access point or device perform a mutual authentication by exchanging several management frames as part of the connection process. To become authenticated and associated, the client sends an association request frame, and the access point responds with an association response frame, and the process is complete.
A media player acting as a client or station must accomplish the similar authentication and association steps to communicate on the network. However, a media player user may only wish to connect and communicate with compatible or similar media players. For example, in some network configurations, the authentication and association process described above allows many 802.11 devices, regardless of the device type, to connect to a network implementing the standard. While the freedom to allow multiple types of devices to connect to a network is desirable in many contexts, when a user desires to create a network of specific types or compatible devices, the freedom associated with the 802.11 standard may become cumbersome. Further, the authentication and association process does not allow a device user to discern the capabilities, compatibility, and characteristics of a connecting device. Rather, as described above, the connecting device must complete the entire authentication and association process to exchange any data. A media player user may, therefore, have only a limited indication of the device type and no indication of the type or content of the device's data until the connection process is complete.
In other types of network connections, presence technology allows network stations to publish their availability for network interaction. In general, presence information indicates a particular user's ability and willingness to communicate with other network users. Presence information, or presence state, is communicated over the network to a presence service or directly to a presence-enabled device. Either directly or via the presence service, the information is distributed to other network users to convey the user's availability for present network communication or interaction.
A media player or other computing device that is connected to a network may stream media content to other connected devices. While receiving streaming media content, connected devices may also publish presence state information. Further, users may choose to override their presence state by, for example, selecting a “busy” state while they are “online” and able to receive streamed content. However, merely being able to choose a presence state may broadly limit a user's ability to receive content while still allowing other users to see that, while a “busy” device may not be available for communication, it is still within range and connected to the network. If a large number of devices are within range, sifting through all connected devices to find a device with which a user wishes to communicate may become unmanageable. Likewise, merely publishing presence state information, without more, may not provide either sending or receiving stations with adequate information to attempt a connection with an available device.